Adjustable safety cable

ABSTRACT

The disclosed safety apparatus for the erection of structure and method for erection thereof comprises a first substantially vertical support, a second substantially vertical support and a supporting cable extending between said first and second supports, wherein said vertical supports are configured to be adjustable in length and each includes a first fixing means and a second fixing means such that the length of a support may be adjusted by releasing said first fixing means and then re-fixing said first fixing means after said adjustment has been made.

BACKGROUND OF THE INVENTION

In order to erect structures such as buildings, scaffoldings are usuallyrequired to be erected prior to any other work carried out on thebuilding itself.

People who erect scaffoldings are known in the art as scaffolders andare required to erect such scaffolds in conditions that, by necessity,place them at risk of falling from a relatively high elevation duringthe course of their work.

1. Field of the Invention

The present invention relates to a safety apparatus for the erection ofstructures, which provides safety to users before they are placed atrisk.

2. Description of the Related Art

Numerous types of safety apparatus exist to prevent such occurrences,such as described in United Kingdom Patent 2 311 554. However, suchsystems require the scaffolder to first escalate the scaffold,irrespective of its height without the benefit of being safely attachedto any safety apparatus, and only being able to anchor himself to saidsafety apparatus once he has reached his area of work.

Such a problem is encountered both at the time of climbing onto thescaffold, for instance at the beginning of the working day and,subsequently, also at the time of coming off the scaffold, for instanceat the end of the working day. Moreover, each time a higher level ofscaffolding requires erecting, scaffolders are hence required to climbup the scaffolding and existing apparatus do not allow them to do sowhilst benefiting from being safely attached to any safety apparatus.Indeed, a scaffolder must first release his anchor from said safetyapparatus, then climb up to the new level of scaffolding whereafter heran secure the existing apparatus in place, said scaffolder beingconstantly at risk of falling. Only then can he and his co-workersanchor to said safety apparatus.

BRIEF SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provideda safety apparatus for the erection of structures, comprising a firstsubstantially vertical support; a second substantially vertical support;and a supporting cable extending between said first and second supports,wherein said vertical supports are configured to be adjustable in lengthand each includes a first fixing means and a second fixing means suchthat the length of a support may be adjusted by releasing said firstfixing means and then refixing said first fixing means after saidadjustment has been made. The invention therefore provides a means forproviding constant safety to said scaffolder such that he is constantlytethered to said safety apparatus whilst scaling and erectingscaffoldings, independently of the height that said scaffold must beerected to:

According to a second aspect of the invention, there is provided amethod of erecting safety apparatus during the assembly of a structure,comprising the steps of attaching the first substantially verticalsupport to said structure; attaching the second substantially verticalsupport to said structure; extending a cable between said first andsecond supports and attaching a safety harness to said cable, whereinsaid vertical supports are configured to be adjustable in length andeach includes a first fixing means and a second fixing means such thatthe length of a support may be adjusted by releasing said first fixingmeans and then refixing said fixing means after said adjustment.

The invention will now be described by way of example only withreference to the following drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is an isometric view of a scaffold erected;

FIG. 2 is an isometric view of a scaffold erected, with the safetyapparatus in place;

FIG. 3 is a side view of the first and second substantially verticalsupports and of the supporting cable of said safety apparatus, whichembodies the present invention;

FIG. 4 is a side view of a detail of the first substantially verticalsupport of said safety apparatus, illustrating the anchoring of thesupporting cable and the external strengthener component at the base ofan upper tube of said first substantially vertical support;

FIG. 5 is a perspective view of the device which embodies first andsecond fixing means;

FIG. 6 is a side view of a system of pulleys and rope combination, usedto adjust the height of both an upper and lower tube of a substantiallyvertical support relative to on another;

FIG. 7 is an isometric view of a first level of scaffolding with thesafety apparatus in place;

FIG. 8 details steps performed to adjust the length of the substantiallyvertical supports;

FIG. 9 is an isometric view of a first and second level of scaffoldingwith the safety apparatus in place, wherein the length of sad safetyapparatus has been adjusted;

FIG. 10 shows a first, second and third level of scaffolding with thesafety apparatus in place, wherein the length of said safety apparatushas a been adjusted and said safety apparatus is extended to its maximumlength;

FIG. 11 is an isometric view of a scaffold featuring multiple levelswith the safety apparatus in place, wherein the length of said safetyapparatus has been adjusted; and

FIG. 12 illustrates an alternative embodiment of the invention, whereinmultiple supporting cables are implemented.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows a scaffold 101, comprising of vertical poles 102,horizontal poles 103, transversal poles 104 and flat sections 105. Italso comprises diagonal strengthener poles 106.

Typically, the erection of the scaffold requires firstly, the erectionof the vertical poles 102 and secondly, fitting of the horizontal poles103. Transversal poles 104 are then implemented to confer additionalstability and integrity to the scaffold before the flat sections 105 areput in place. The diagonal strengthener pole 106 are then implemented toconfer additional stability and integrity to the ensemble.

Current safety apparatus for scaffolders who erect this type ofstructure consists mainly of a lanyard tethering a safety harness wornby the scaffolder to any of the scaffold poles that constitute thescaffold. Such a lanyard is typically five feet length, thus restrictingthe working area for any scaffolder wearing this safety apparatus tofive feet either side of the anchoring paint of the lanyard.

Upon completing work necessary to the erection of a higher flat surface,which can be partially achieved whilst standing on the flat surfaceimmediately underneath, a scaffolder must then unhook his lanyard fromits anchoring point on the scaffold, climb to the new higher level ofthe scaffold untethered at the risk of falling from the scaffold inorder to reach the parts of the ensemble that requires further work,such as tightening bolts or fixtures, and then set up the safetyapparatus again.

Once in place, he can then tether his lanyard to safety apparatus andcarry out further tasks. Alternatively, should other scaffolders beworking on said scaffold with the first scaffolder, they also mustunfasten their lanyard from safety apparatus and climb to the higherlever untethered, at the risk of falling from the scaffold.

FIG. 2 shows the same scaffold 101 fully erected and equipped with thepresent invention.

A first substantially vertical support 201 consists of a lower tube 204and an upper tube 205. Said lower tube 204 has a larger diameter thanupper tube 205 so that upper tube 205 may slide vertically within saidlower tube 204. The lower tube 204 is attached to transversal poles 104of scaffold 101 by way of second fixing means 214 and 215. The uppertube 205 is attached to transversal poles 104 of scaffold 101 by way offirst fixing means 216 and 217.

The upper tube 205 features an anchoring head 211 located at its lowerextremity and protruding from the lower tube 204 through a slotimplemented along at least part of the length of lower tube 204. Uppertube 205 also includes an internal strengthener component 222, thesection of which can be square, triangular or dodecahedral. An externalstrengthener component 213 extends between the lower anchoring point 211arc an upper anchoring point 212 situated at the upper extremity ofupper tube 205. A supporting cable 203 extends between said firstsubstantially vertical support 201 and a second substantially verticalsupport 202.

Said substantially vertical support 202 has an identical structure tofirst substantially vertical support 201 in that it includes a lowertube 206 and an upper tube 207, the diameter of said lower tube 206being larger than that of upper tube 207 so as to enable the upper tube207 to slide vertically within lower tube 206. The upper tube 207features an anchoring point 208 at As lower extremity and an anchoringpoint 209 situated at its upper extremity. Upper tube 207 also includesan internal strengthener component 223, the section of which can besquare, triangular or dodecahedral. An external strengthening cable 210extends between both anchoring points. The lower tube is attached totransversal poles of scaffold is 101 by way of second fixing means 218and 219 and upper tube 207 is attached to transversal poles of scaffold101 by way of first fixing means 220 and 221.

FIG. 3 provides a more detailed view of the anchoring means for thesupporting cable 203 extending between said first and second supports.

Supporting cable 203 passes through a first clamping device 301 locatedon the anchoring point 211 which is itself located on the lowerextremity of the upper tube 206 of the first substantially verticalsupport 201. The supporting cable 203 then passes through a seconddamping device 302 identical in all points to damping device 301.Clamping device 302 is rigidly attached to upper tube 205. Supportingcable 203 is then further supported by pulley 303 implemented at theupper extremity of upper tube 205, which translates the direction of thesafety cable from a vertical direction to a horizontal direction.Supporting cable 203 then extends between said upper extremity of theupper tube 205 of the substantially vertical support 201 and the upperextremity of upper tube 207 of second substantially vertical support202.

The second substantially vertical support 202 is identical in structureand components to the first substantially vertical support 201 but doesnot feature a first or a second clamping device. However, the upper tube207 features attachment means 304 at its upper extremity in order tosafely anchor the extremity of the supporting cable 203.

FIG. 4 provides a more detailed view of the clamping devices implementedto secure the supporting cable 203 as well as the external strengtheningcable 213. Anchoring point 211 is an integral part of upper tube 205 andprotrudes from a slot 409 implemented along at least part of the lengthof lower tube 204. Clamping device 301 features an upper opening 401through which supporting cable 203 enters the clamping device. It alsofeatures a lower opening 402 through which the cable exits the clampingdevice. The clamping operation is implemented by way of an anteriorplate 403 against which supporting cable 203 is clamped by a posteriorplate 404. The posterior plate 404 is pressed against the cable and theanterior plate 403 by way of a tightening screw and bolt combination405.

The supporting cable 203 then passes through a second damping device302, which is identical in all points to the damping device 301.

Supporting cable 203 is tensed once h has been threaded through clampingdevices 301, 302 and safely anchored to anchoring point 209, and isclamped in place by tightening the screw and bolt combination 405. Ineffect, clamping device 302 provides the primary damping point, whereasclamping device 301 assumes the function of a redundant, additionalsafety clamping point should the primary damping device 302 fail.

Part of the anchoring point 211 protrudes and a cavity 410 isimplemented at the extremity of this protuberance in order to facilitatethe anchoring of the external strengthener component 213 to saidanchoring point. Said external strengthener component 213 is attached toa first loop 406 that includes a threaded extremity, said threadedextremity is screwed to one end of a double-ended tightening loop 407, ahook 408 also including a threaded extremity is screwed to the other endof the double ended tightening loop 407. The sharp end of said hook 408is then passed through the cavity 410. Upon rotating the double-endedtightening loop 407, the tension of the external strengthening cable 213is increased and therefore increases the overall rigidity and integrityof the upper tube 205.

FIG. 5 illustrates a perspective view of said first and second fixingmeans 214, 215, 216, 217, 218, 219, 220 and 221. Said fixing meanscomprise two cylindrical brackets 501 and 502, diametrically opposedsuch that bracket 501 is secured around substantially vertical support201 and bracket 502 is secured around any pole forming part of scaffold101, preferably a transversal pole, such as transversal pole 104. Saidbracket 501 comprises a first halt cylinder 503 and a second halfcylinder 504 articulated by a hinge 505. Said half cylinders 503 and 504may be clasped together by way of locking means 506.

The half cylinder 503 features an inner plate 507 with a permanent layerof PTFE material implemented to confer the apparatus increased grip overthe substantially vertical support. The second half cylinder 504 whichfaces the outside of said substantially vertical support features threethreaded holes 508, 509 and 510, preferably equidistant from one anotherand implemented on an imaginary line dividing the half cylinder 504along the sense of its curve. Screw devices 511, 512 and 513 have athread that compliments the thread implemented in openings 508, 500 and510. An internal plate 514 with a curvature sensibly similar to thecurve defined by the half cylinder 504 is pressed, against saidsubstantially vertical support by way of screwing and thereby tighteningscrew device 511 into opening 508, screw device 512 through opening 509and screw device 513 through opening 510, at which point they applypressure against the curved plate 514, which itself clasps saidsubstantially vertical support against plate 507.

Said bracket 501 is mounted by way of welding, or other appropriateprocess, to an extension arm 515, the section of which is substantiallybut non-exclusively circular. Said extension arm 515 is itself mountedonto a base square plate 516 by way of welding, or any other appropriatemeans. Said base square plate 516 has threaded holes 517 implemented ateach of its four comers.

An additional bracket 502, identical in all points to first bracket 501,is fixed to bracket 501 by bolting together their respective base squareplates 516 and 518 through the four threaded openings 517 on squareplate 516 and corresponding threaded openings 519 on square base plate518. Said bracket 502 is fixed to bracket 501 in such a way that thecylinders respectively delimited by brackets 501 and 502 areperpendicular to one another. Thus, we have described fixing means ofthe type erred to in FIG. 2 as 214, 215, 216, 217, 218, 219, 220 and221, which enable the safe anchoring of the ensemble of thesubstantially vertical supports to transversal poles, which are astrengthening part of scaffold 101 themselves.

FIG. 6 shows an implementation of a system of pulleys and ropecombination, which is used to slide upper tube 205 independently oflower tube 204. Said system comprises a first ensemble of pulleys 601,rigidly fixed to lower tube 204 of first substantially vertical support201. Said system also comprise a second ensemble of pulleys 602, itselfrigidly fixed to upper tube 205 of first substantially vertical support201. A rope 603 passes through both ensembles of pulleys 601 on lowertube 204 and 602 on upper tube 205 and is threaded through said ensembleof pulleys in such a way that pulling on said rope 603 would raise uppertube 205 independently of lower tube 204 and feeding the rope throughthe ensemble of pulleys would, on the contrary, lower upper tube 205within lower tube 204. Alternatively, should rope 603 be manoeuvredabove the lower tube 204, the effect of pulling rope 603 through theensemble of pulleys 601, 602 would raise the lower tube 204independently of upper tube 205 and feeding said rope 603 through theensemble of pulleys 601, 602 would lower lower tube 204 independently ofupper tube 205.

The second substantially vertical support 202 is equipped with anidentical system of pulleys and rope combination, in order to adjust theheight of both substantially vertical supports 201 and 202 such that thesupporting cable 203 remains parallel to the structure and is attachedat all times.

FIG. 7 shows the first erected level of a scaffold 701, which typicallydoes not yet require scaffolders to equip themselves with any safetydevice, said structure being typically under six toot high.

Said scaffold comprises a combination of vertical poles 715 andhorizontal poles 716 and four transversal poles 703, 704, 705 and 706.It further comprises flat surface 702, typically wooden planks restingon the ensemble delimited by the poles so that scaffolders, fitters orbuilders, can manoeuvre and carry out their working tasks on thescaffold. The safety apparatus is implemented at this stage of theerection of the structure.

The safety apparatus comprises a first substantially vertical support201, itself comprising a lower tube 204 and an upper tube 205, saidlower tube 204 having a bigger diameter than said upper tube 205, so asto allow upper tube 205 to slide vertically within lower tube 204.

The safety apparatus also comprises a second substantially verticalsupport 202 of a structure similar to first substantially verticalsupport 201 in that it includes a lower tube 206 and an upper tube 207,said lower tube 206 having a larger diameter than upper tube 207, so asto allow upper tube 207 to slide vertically within lower tube 208.

A safety cable 203 extends between first substantially vertical support201, which is attached to scaffolding 701 by way of second fixing ismeans 214 and 215 respectively bracketing transversal poles 703 and 704,and second substantially vertical support 202, which is attached toscaffolding 701 by way of second fixing means 218 and 219, respectivelybracketing transversal poles 705 and 706.

Said safety apparatus is implemented at this stage of the erection ofthe structure to enable scailolders to attach their respective safetyharnesses to the apparatus whilst still being on the ground, therebybenefiting from the safety conferred by the apparatus as soon as thescaffolders start escalating said structure.

A scaffolder 707 equipped with a safety harness 709 is depicted as stoodon flat surface 702. He is tethered to safety cable 203 by way of acable 711 attached to a cable clamping device 713, preferably of thetype known as inertia reel. Another scaffolder 708, equipped with asafety harness 710 is tethered to safety cable 203 by way of a cable 712attached to a cable clamping device 714, also preferably of the typeknown as inertia reel, is depicted still on the ground.

Safety cable clamping devices 713 and 714 are preferably of the typeknown as inertia reel for the purpose of enabling a scaffolder 708 tosecure his harness 710 to the safety cable 203 whilst still on theground before climbing onto the scaffold 701 and putting himself at riskof subsequently falling from a high elevation.

Said inertia reel is well known to those skilled in the art and isdesigned to function along the same principle as a car safety belt. Itwill allow an attachment cable to unreel in the case of a scaffolderescalating or descending from a structure such as a scaffold, but itwill prevent the cable from unreeling in the case of an abrupt cabletension such as may arise in an accidental fall from said structure.

Thus, before erecting the safety apparatus, handlers will ensure thatthe respective leads of the attachment cables of said inertia reels 713and 714 are secured to any anchoring means on the ground, so that, uponcompleting the setting up of the safety apparatus, scaffolder 708 cansafely attach the lead of inertia reel 714 to his safety harness 710 andscale scaffold 701 to reach the position of scaffolder 707 in totalsafety.

The safety cable 203 must always stand above the head of thescaffolders. Therefore, as the structure is being erected, the height ofsafety cable 203 relative to the height of the scaffolders at work willsubsequently have to be adjusted. FIG. 8 details the steps required toadjust the height of said safety cable appropriately.

At step 801 it is determined that a new, higher level of structurerequires erecting. At step 802 the question is asked as to whether thesafety cable and therefore the safety apparatus in its ensemble is highenough to remain above the head of the scaffolders and thereby providesafety once the new, higher level has been erected. If answered in theaffirmative, said new higher level can be built at step 810 withoutproceeding with any further adjustments of the safety apparatus.However, if answered in the negative, the safety apparatus requiresadjustment so that said safety cable will still be above the head of thescaffolder once the new higher level has been erected.

At step 803 the first fixing means 216 and 217 are released so as toenable upper tube 205 of first substantially vertical support 201 toslide vertically within lower tube 204 by way of the system of pulleysand rope combination 601, 602, 603 until such time as it reaches anappropriate height at step 804. At step 805 the first fixing means 215and 217 are then re-fixed to the structure and secured again. Thisthree-step procedure is repeated with the first fixing means 220 and 221of upper tube 207 of second substantially vertical support 202.

At step 806 a question is asked as to whether the safety cable is nowhigh enough after the adjustment has taken place for the work to becarried out. When answered in the affirmative the new higher level ofthe structure can be erected as at step 810. However, should safetycable 203 and the safety apparatus still not reach the required height,for instance if the maximum elevation of the safety apparatus stood onthe ground has been reached, then at step 807 the second fixing means214 and 215 are released so as to enable lower tube 204 of firstsubstantially vertical support 201 to slide vertically over upper tube205 by way of the system of pulleys and rope combination 601, 602, 603until such time as it reaches an appropriate height at step 808. At step806 the second fixing means 214 and 215 are then re-fixed to thestructure and secured again. This three-stop procedure is repeated withthe second fixing means 218 and 219 of lower tube 206 of secondsubstantially vertical support 202. At which point the operation revertsback to step 803 where the first fixing means, located an the uppertubes are released, the upper tubes can slide upwards to achieve therequired height and the first fixing means are secured in place. Thus,the appropriate height for the safety apparatus is now achieved and thenew higher level of the structure can be erected.

Throughout the nurse of the adjustment that has been described, thescaffolders carrying out this adjustment and erecting said structurestill benefit from a safe tethering to safety cable 203 that willprevent any accidental fall from said structure.

FIG. 9 shows a scaffold 701 from FIG. 7 where an additional higher levelof scaffold has been implemented by way of vertical poles 901,horizontal poles 902, transversal poles 903 and 904 and flat surface904. At this stage, the height of the scaffold does not yet requireupper tubes 205 and 207 to be attached to the structure. The height ofthe safety cable 203 has however been adjusted with regard to itsrespective heights as depicted in FIG. 7 and said adjustment has beencarried out by way of a system of pulleys and rope combination 601, 602,603. Additionally, further integrity has been provided to the safetyapparatus by releasing second fixing means 215 and 219 from theiranchoring to transversal poles 704 and 706 respectively, andre-anchoring to new, higher transversal poles 903 and 904.

Scaffolder 707 has been able to carry out all the aforementionedadjustments in total safety. Moreover, scaffolder 708 is still able toanchor his harness 710 to safety cable 203 by attaching the lead ofattachment cable 712 on inertia reel 714 whilst still on the ground.

FIG. 10 again shows a scaffold 701 from FIGS. 7 and 9, where anadditional higher level of scaffold has been implemented by way ofvertical poles 1001, horizontal poles 1002, transversal poles 1003,1004, 1005, 1006, 1008 and 1009 and flat surface 1007. At this stage,the height of the scaffold does require upper tubes 205 and 207 to beattached to the structure, by attaching first fixing means 216 and 217to transversal poles 1003 and 1004 respectively, and attaching firstfixing means 220 and 221 to transversal poles 1005 and 1006respectively. The height of the safety cable 203 has initially beenadjusted with regard to its restive heights as depicted in FIGS. 7 and 9and said adjustment has been carried out by way of a system of pulleysand rope combination 601, 602, 603. The safety apparatus is heredepicted as having reached its maximum extension, which reachesgenerally between five and ten meters, preferably reaches seven meters.

Scaffolder 707 has been able to carry out all the aforementionedadjustments in total safety. Moreover, scaffolder 708 is still able toanchor his harness 710 to safety cable 203 by attaching the lead ofattachment cable 712 on inertia reel 714 whilst still on the ground.

FIG. 11 again shows a scaffold 701 from FIGS. 7, 9 and 10, whereadditional higher levels of scaffold have been implemented by way ofvertical poles 1101, horizontal poles 1102, transversal poles 1103,1104. 1105 and 1106 and flat surfaces 110 and 1108. At this stage, theheight of the scaffold has required the length of the safety apparatusto be adjusted such that supporting cable 203 is elevated to a heightbeyond the maximum elevation of said safety apparatus whilst the lowerextremities of the respective lower tubes of its two substantiallyvertical supports rest on the ground. Steps 801 to 810 have thereforebeen followed and, in order to arrive at the situation represented inFIG. 11, the following actions have successively taken place;

In order erect further levels of scaffold 701 it is determined that thesafety cable will not be high enough after the adjustment as at step806, since the safety apparatus has already reached its maximumextension. The second fixing means 214 and 215 are therefore releasedfrom the transversal poles 706 and 903 respectively. Alternatively,first fixing means 216 may also be released from transversal pole 1003in order to slide lower tube 204 further up than what would be the caseif this particular first fixing means was left in place. Lower tube 204then slides upwards along the length of upper tube 205 by way of thesystem of pulleys and rope combination 601, 602 and 603. Second fixingmeans 214 and 215 are then respectively refixed to transversal poles1003 and 1008. The above operation is then repeated for the secondsubstantially vertical support, the second fixing means 218 and 219 ofwhich are released from the transversal poles 705 and 904 respectively.Alternatively, first fixing means 220 may also be released fromtransversal pole 1005 in order to provide more clearance to slide lowertube 206 further up along the length of upper tube 207. Said lower tube206 then slides along in an upward direction along the length of uppertube 207. Second fixing-means 218 and 219 are then respectively securedto transversal poles 1005 and 1009.

Subsequently, first fixing means 217 is released from transversal pole1004 and the length of the safety apparatus is adjusted by way of thesystem of pulleys and rope 601, 602 and 603. Similarly, first fixingmeans 221 is released from transversal pole 1006 and the length of thesecond substantially vertical support is likewise adjusted so thatsupporting cable 203 reaches an appropriate height above the head of thescaffolders.

A new level of structure delimited by flat surface 1107 can now beerected. Upon erection of this level the length of the safety apparatusis again adjusted by way of the system of pulleys and rope combination601, 602 and 603. Upon completing this adjustment a new higher level ofscaffold 701 which is delimited by flat surface 1108 can now be erected.

Upon completion of the assembly of this new higher level, first fixingmeans 216 and 217 of upper tube 205 can now be attached to transversalpoles 1103 and 1104 respectively. Likewise, first fixing means 220 and221 of upper tube 207 can now be attached to transversal pole 1105 and1106 respectively.

Thus, we have now described a method of erecting safety apparatus duringthe assembly of a structure which comprise the steps of attaching afirst substantially vertical support 201 to said structure, to attachthe second is substantially vertical support 202 to said structure, toextend a supporting cable 203 between said first and secondsubstantially vertical supports 201, 202 and attach a safety harness 709or 710 to said supporting cable 203, wherein said vertical support 201,202 are configured to be adjustable in length and each includes a firstfixing means 216, 211, 220, 221 and a second fixing means 214, 215, 218,219, such that the length of a support may be adjusted by releasing saidfixing means and then re-fixing said fixing means after said adjustmentas according to steps 801 to 810.

In a preferred embodiment of the present invention, substantial verticalsupport 201 is equipped with spring-loaded supporting foot 1109. Saidsupporting foot 1109 is implemented at the lower extremity of lower tube204 of said substantially vertical support 201. It is configured toconfer additional stability to safety apparatus in its ensemble, by wayof transferring part of the weight of the safety apparatus in itsensemble to the lowest transversal pole 104 the base of saidspring-loaded supporting foot is resting on.

As most of the total weight of the safety apparatus is in its ensembleit is supported by first and second fixing means of each substantiallyvertical supports 201 and 202, upon performing the length adjustment inorder for supporting cable 203 to be adjusted to an appropriate heightsaid spring-loaded supporting foot 1109 then rotates downward as itcomes into contact with the underside of the next higher transversalpole, then slide along the external diameter of said pole in a sensiblyvertical direction. Upon the extremity of said spring-loaded supportingfoot 1109 having slid along the full external diameter of said nexthigher transversal pole, said extremity being now situated above nexthigher transversal pole, said spring action derived from thespring-loaded characteristic of said supporting foot actuate therotation of said supporting foot back to a position sensiblyperpendicular to substantially vertical support 201 and parallel tosupporting cable 203. Said spring-loaded supporting foot 1109 can thensupport part of the weight of safety apparatus in its ensemble on saidnext, higher transversal pole. A spring-loaded foot 1110, identical inconfiguration, characteristics and function to spring-loaded supportingfoot 1109, is implemented at the lower extremity of lower tube 206 ofsubstantially vertical support 202, such that both substantiallyvertical supports 201, 202 are evenly supported in this way.

An alternative embodiment of the present invention exist wherein thelower and upper tube configuration of each said substantially verticalsupport remain identical in all points, however the upper extremities ofupper tube 205 and 207 are configured to accommodate multiple supportingcables.

For example, FIG. 12 illustrates the implementation of a secondsupporting cable 1201, which has been implemented between the firstvertical support 201 and the second vertical support 202.

Upper extremity 209 of upper tube 207 features two sensibly parallelattachment means 304, wherein one attachment means provides safeanchoring for supporting cable 203 and the second attachment means,sensibly parallel to first attachment means 304, provides safe anchoringfor second supporting cable 1201. Said supporting cables 304 and 1201can be clamped by clamping devices 301 and 302.

Moreover, said clamping devices 301, 302, the components of which aredescribed in detail in FIG. 4, can be adapted to accommodate multiplecables 203, 1201 by implementing as many individual ensembles ofcomponents necessary to the clamping of said cables as there aresupporting cables. Said multiple ensembles of damping device componentsare sensibly parallel to one another and implemented side-be-sled on theupper tube.

The benefit of this alternative embodiment of the invention is to enablescaffolders or builders working on a same flat surface of a structure tocross one another's path without incurring the risk of entangling thecable attachment of their respective inertia reel and thereby unreelingsaid cable attachment further which, in the case of an accidental fall,would increase the pendulum effect affecting said falling scaffolder.

What is claimed is:
 1. Safety apparatus for people working on astructure, comprising: a first substantially vertical support comprisinga lower part and an upper part movable with respect to said lower partsuch that said first support is adjustable in length; said upper partand said lower part comprise an upper tube and a lower tuberespectively; said upper tube comprises an internal strengtheningcomponent and an external strengthening cable; a tightening loopconfigured to tense said external strengthening cable and tension withinsaid external strengthening cable being adjustable by said tighteningloop; first fixing means configured to attach said upper part to astructure; second fixing means configured to attach said lower part tosaid structure; and a supporting cable extending from said upper part ofsaid first support; wherein said supporting cable is an overhead safetycable for tethering people; when said apparatus supports said supportingcable at a lower height when said lower part is attached to a structureand said upper part is unattached; and when a length of said firstsupport is increased and said upper part is attached to said structure,such that said apparatus supports said supporting cable at a higherheight.
 2. Apparatus according to claim 1, wherein said apparatuscomprises a second substantially vertical support comprising: a secondlower part and a second upper part movable with respect to saidsecond-lower part such that'said second support is adjustable in length;third fixing means configured to attach said second upper part to astructure; fourth fixing means configured to attach said second lowerpart to said structure; and said supporting cable extends between saidfirst support and said second support.
 3. Apparatus according to claim1, wherein said lower tube has a first diameter, said upper tube has asecond diameter and said first diameter is different from said seconddiameter so that said upper and lower tubes can slide verticallyindependently of one another.
 4. Apparatus according to claim 2, whereinsaid supporting cable is one of multiple supporting cables extendingbetween said first support and said second support.
 5. Apparatusaccording to claim 2, wherein said first and second supports areconfigured to support said supporting cable while said second fixingmeans and said fourth fixing means are released and lengths of saidfirst and second supports are adjusted to raise said lower part of saidfirst support and said second lower part of said second support, andsubsequently while said first fixing means and said third fixing meansare released and said first upper part of said first support and saidsecond upper part of said second support are raised.
 6. Apparatusaccording to claim 1, wherein said apparatus further comprisescable-clamping devices configured to tense said supporting cable, andtension within said supporting cable is adjustable by saidcable-clamping devices.
 7. Safety apparatus for people working on astructure, comprising: a first substantially vertical support comprisinga first lower part and a first upper part movable with respect to saidfirst lower part such that said first support is adjustable in length;said first support further comprising a first spring-loaded footattached to said first lower part such that when said first lower partis raised, said first spring-loaded foot rests on said structure; firstfixing means configured to attach said first upper part to a structure;second fixing means configured to attach said first lower part to saidstructure; a second substantially vertical support comprising a secondlower part and a second upper part movable with respect to said secondlower part such that said second support is adjustable in length; saidsecond support further comprising a second spring-loaded foot attachedto said second lower part such that when said second lower part israised, said second spring-loaded foot rests on said structure; thirdfixing means configured to attach said second upper part to saidstructure; fourth fixing means configured to attach said second lowerpart to said structure; and a supporting cable extending from said upperpart of said first support and said supporting cable extending betweensaid first support and said second support; wherein said first supportis configured to support said supporting cable while said second fixingmeans is released and a length of said first support is adjusted toraise said first lower part of said first support, and subsequentlywhile said first fixing means is released and said first upper part israised; and said second support is configured to support said supportingcable while said fourth fixing means is released and the length of saidsecond support is adjusted to raise said second lower part of saidsecond support, and subsequently while said third fixing means isreleased and said second upper part is raised.
 8. Apparatus according toclaim 7, wherein said first upper part and said first lower partcomprise an upper tube and a lower tube respectively.
 9. Apparatusaccording to claim 8, wherein said lower tube has a first diameter, saidupper tube has a second diameter and said first diameter is differentfrom said second diameter-so that said upper and lower tubes can slidevertically independently of one another.
 10. Apparatus according toclaim 7, wherein said supporting cable is one of multiple supportingcables extending between said first support and said second support. 11.Apparatus according to claim 7, wherein said apparatus further comprisescable-clamping devices configured to tense said supporting cable, andtension within said supporting cable is adjustable by means of saidcable-clamping devices.
 12. A method of erecting safety apparatus forpeople working on a structure, in which said safety apparatus comprises:a first substantially vertical support comprising a lower part and anupper part movable with respect to said lower part such that said firstsupport is adjustable in length; said upper part and said lower partcomprise an upper tube and a lower tube respectively; said upper tube isequipped with an internal strengthening component and an externalstrengthening cable; a tightening loop configured to tense said externalstrengthening cable, and tension within said external strengtheningcable being adjustable by said tightening loop; a first fixing means; asecond fixing means; and a supporting cable extending from said upperpart; said method comprising the steps of: attaching said lower part toa structure using said second fixing means such that said apparatussupports said supporting cable at a lower height while said upper partis unattached; using said supporting cable as an overhead safety cablefor tethering people; and adjusting a length of said vertical supportand attaching said upper part to said structure using said first fixingmeans, such that said apparatus supports said supporting cable at ahigher height.
 13. A method of erecting safety apparatus according toclaim 12, wherein said apparatus further comprises a secondsubstantially vertical support comprising: a second lower part and asecond upper part movable with respect to said second lower part suchthat said second support is adjustable in length; third fixing meansconfigured to attach said second upper part to a structure; fourthfixing means configured to attach said second lower part to saidstructure; and said supporting cable extends between said first supportand said second support.
 14. A method according to claim 13, whereinsaid method further comprises the step of extending multiple cablesbetween said first support and said second support.
 15. A methodaccording to claim 13, comprising the further steps of: releasing saidsecond fixing means and said fourth fixing means and adjusting thelength of said first support and said second support to raise said lowerpart of said first support and said second lower part of said secondsupport; and releasing said first fixing means and said third fixingmeans and raising said first upper part of said first support and saidsecond upper part of said second support.
 16. A method according toclaim 12, wherein said structure is a scaffold structure, and saidmethod further comprises the additional step of implementing anadditional higher level of scaffold, after performing said step ofattaching said-lower part to said structure using said second fixingmeans such that said apparatus supports said supporting cable at a lowerheight while said upper part is unattached.
 17. A method of erectingsafety apparatus for people working on a structure, in which said safetyapparatus comprises: a first substantially vertical support comprising afirst lower part and a first upper part movable with respect to saidfirst lower part such that said first support is adjustable in length;said first support further comprising a first spring-loaded footattached to said first lower part such that when said first lower partis raised, said first spring-loaded foot rests on said structure; asupporting cable extending from said first upper part; a first fixingmeans; a second fixing means; a second substantially vertical supportcomprising a second lower part and a second upper part movable withrespect to said lower part such that said second support is adjustablein length; said second support further comprising a second spring-loadedfoot attached to said second lower part such that when said second lowerpart is raised, said second spring-loaded foot rests on said structure;a third fixing means configured to attach said second upper part to astructure; a fourth fixing means configured to attach said second lowerpart to said structure; said supporting cable extending between saidfirst support and said second support; said method comprising the stepsof: attaching said first lower part to a structure using said secondfixing means such that said apparatus supports said supporting cable ata lower height while said first upper part is unattached; using saidsupporting cable as an overhead safety cable for tethering people;adjusting a length of said first support and attaching said first upperpart to said structure using said first fixing means, such that saidapparatus supports said supporting cable at a higher height; releasingsaid second fixing means and said fourth fixing means and adjusting thelength of said first support and said second support to raise said firstlower part of said first support and said second lower part of saidsecond support; and releasing said first fixing means and said thirdfixing means and adjusting the length of said first support and saidsecond support to raise said first upper part of said first support andsaid second upper part of said second support.
 18. A method according toclaim 17, wherein said method further comprises the step of extendingmultiple cables between said first support and said second support. 19.A method according to claim 17, wherein said structure is a scaffoldstructure, and said method further comprises the additional step ofimplementing an additional higher level of scaffold, after performingsaid step of attaching said first lower part to said structure usingsaid second fixing means such that said apparatus supports saidsupporting cable at a lower height while said first upper part isunattached.